Product Description:

The PSI65C0.731-W1 is a medium-frequency inverter built by Bosch Rexroth Indramat within the PSI Frequency Inverters series. It converts a three-phase 400–480 VAC supply into controlled medium-frequency output for induction heating, brazing, and other thermal processes used in automated production lines. I/O and timer synchronization are handled over Ethernet lines routed to the front panel.

Control functions are executed by a TriCore processor, allowing management of firing angles and safety interlocks. Because the inverter is water cooled, the 850 W of cabinet losses generated at maximum current are removed by a dedicated heat exchanger rather than cabinet fans. The enclosure has an IP20 rating, so it must be mounted inside a cabinet to avoid contact with live parts. Mains nominal current reaches 330 A, so supply breakers and busbars must be sized accordingly, while the separate cabinet-cooling circuit may demand up to 660 A during full regenerative operation. During high-duty cycles, dissipated energy can climb to 4400 W, and the internal chopper section can deliver up to 2400 A of primary current to the work coil for rapid heat buildup in conductive materials.

To maintain stable thermal operation, the cooling loop must deliver at least 10 L/min while keeping supply water below 30 °C. Pressure should not exceed 10 bar, and the expected drop across the heat exchanger is 0.65 bar. Under these conditions, the inverter avoids an additional 100 W of basic control-cabinet losses from accumulating. On the electrical side, the resonant tank can draw up to 120 kA of secondary current, a level suited for thick workpieces that need deep heat penetration. These operating points are supervised through the timer interface so current limits, flow rates, and temperature alarms remain within set thresholds.